I have an ASUS wrx80, and I am looking at upgrading the graphics card from gt970 to AMD 6700xt or something around that. The problem is that some graphics cards take 2 power cables, and my 800w PSU does not support any more power cables. This is because I have plugged the 2 power cables into the bottom part of the motherboard, which feeds more power if needed.
So if I plug in a GPU which has 2 power cables, then would the GPU be able to feed off the power that’s going into the motherboard from the 2 power headers?
Power supply is not an issue, i guess that only 300w or so is being used and I have 800w psu, it’s just making the gpu can tap into the power supply.
The motherboard will only supply 75w max to a pcie port. Your new card needs two plugs because of current limits in the wires themselves according to the ATX standard (I believe). Most of the time, a card won’t function without both plugs.
That said, buy a splitter and in reality you’d be fine if your PSU 12v rail can provide enough power. But if you don’t have enough plugs, there’s a good chance that it can’t.
In case that you do not have many power hungry PCIe cards disconnect the connectors at the bottom of the mainboard and plug them into the GPU. The motherboard can provise 75Watts to each PCIe port and since this motherboard has loads of PCIe ports you can and should connect those connectors at the bottom when you have many power hungry devices. Your GPU still only gets 75Watts from the slot, so the rest of the power comes from the direct connections. So in your case plug them out of the mainboard and into the GPU. Hope this helps as an explanation.